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Progressive Flat Water Assn

What EPA’s and Washington’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
335 people
Connections
84
Water source
Groundwater bought from another system
Based in
Tonasket, WA
County
Okanogan
Owner
Private
The ZIP code it serves

98840

The short answer

1 result is above the health goal. The worst: Lead, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2002 to 2023.

Total trihalomethanes (TTHM) and haloacetic acids (HAA5): Washington’s own results, samples taken from Sept. 27, 2021 to Aug. 12, 2024.

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

5.2ppb

90th percentile, 2021 to 2023

In the latest period, 9 in 10 homes sampled were at or below 5.2 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits1

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

3.5ppb

Highest yearly average, 2021 to 2024

2024: not found

Averaged by year, the highest was 3.5 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2024, the latest year on file, it wasn’t found in its one sample.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Haloacetic acids (HAA5)

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)June 1, 2021 to June 30, 2021—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM) and haloacetic acids (HAA5) results here are Washington’s own from 2021 on, with EPA’s national file for 2012 to 2019. Progressive Flat Water Assn’s own annual report, which it must send you every year, has the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Washington’s results run from Sept. 27, 2021 to Aug. 12, 2024.

Testing your own tap

Progressive Flat Water Assn’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Washington certifies.

The 2 labs Washington certifies closest to the area Progressive Flat Water Assn serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Okanogan County Public Health Laboratory

    Okanogan, WA · under a mile

    Certified for bacteria, nitrate

    (509) 422-7140

  • Anatek Labs, Inc - Wenatchee

    Wenatchee, WA · about 71 miles

    Certified for bacteria

    (509) 701-8362

All 84 certified labs for Washington

Sources

PWSID WA5369650. Rebuilt from EPA data on Oct. 18, 2026.

Also in Okanogan County

All Washington utilities

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